Asthma in the Brown Family

Models and Evidence

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• With your partner, read through the slides to learn about asthma in the Brown Family.

• Remember, read carefully so you are able to answer questions.

• Whenever you have a discussion, try to agree on both your answers and your reasons with your partner!

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Introduction:The Brown family has 2 boys (ages 4 and 7) and a girl (age 10). The boys both have been diagnosed with asthma. When people get asthma, the airways in their lungs become inflamed and become smaller, which makes it harder to breathe. In the last year, the boys have each had 3 serious asthma attacks. Grandma Brown also used to have asthma before she died, but none of the other Brown family members have asthma. The Brown family moved to a small apartment in a poor section of town about 2 years ago after Mr. Brown lost his job. The Browns took the boys to two doctors to figure out what to do about the asthma.

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• After taking the two boys to the doctor, each doctor came up with a model for why the boys have asthma. Here are their models:

Model A:

Dr. Billings says that the boys are allergic to cockroaches and that cockroaches in their apartment are causing the asthma attacks. He does not think their asthma is genetic.

Model B:

Dr. Stone says that the asthma is genetic and runs in the Brown family. The boys’ asthma is inherited from their parents. He believes cockroaches have nothing to do with it.

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• Now you’ll see some evidence to help you decide which model is better.

• Don’t forget to read carefully so you can answer questions about the evidence!

• When answering questions, be sure to try to agree on both your answers and reasons.

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Evidence 1Scientists examined cockroach excrement (poop) and dead cockroach bodies. They found that when the excrement and the dead bodies dry up, they turn to dust. Twenty people volunteered to spend 8 hours in rooms with this cockroach dust. At the end of 8 hours, scientists found the cockroach dust in all 20 people’s lungs. Twenty other people who did not spend time in these rooms did not have any cockroach dust in their lungs. Conclusion: The scientists concluded that dust from cockroach excrement and dead cockroaches can get into people’s lungs.

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• Think about how this evidence relates to each of the models that you have seen.

• On your sheet, draw in the arrow that you think best connects this evidence to each of the models. Draw your arrow for Model A in the first column and your arrow for Model B in the second column.

Question 1 and 2: Arrows

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Question 3: Which is true of Evidence 1? a. Scientists studied 20 people altogether. b. Scientists found that cockroach dust gets into people’s bedrooms. c. All cockroach dust comes from cockroach excrement (poop). d. Twenty people had dust from cockroaches in their lungs.

• Answer these 2 questions about Evidence 1. Write the letter of your best answer on your sheet.

• Be sure to discuss your answers and your reasons with your partner

Question 4: The number of participants used in Evidence 1 was: a. Just enough people b. Too many people c. Too few people d. Enough, but less would have been fine too.

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Evidence 2Scientists studied 385 city children between the ages of 4 and 9. These children all lived in poorly maintained apartment buildings. They tested the children to see if they were allergic to different substances. They tested the children by injecting them with a very small amount of each substance. Children who were allergic showed a reaction- the injection area was red and swollen. The most common allergy sources are recorded in the table below.When children were around these allergy sources, they were more likely to get asthma attacks.The scientists also examined these children’s bedrooms to see which of these allergy sources were in their rooms. They found that the most common allergy source was cockroach dust, which was in 51% of the 385 children’s bedrooms. More children had cockroach dust in their room than any other allergy source.

Conclusion: The scientists concluded that many poor children get their allergies from cockroach dust.

Allergy Source % of Children Allergic

Cockroach Dust 37Dust Mites 35

Cats 23

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• Think about how this evidence relates to each of the models that you have seen.

• On your sheet, draw in the arrow that you think best connects this evidence to each of the models. Draw your arrow for Model A in the first column and your arrow for Model B in the second column.

Question 1 and 2: Arrows

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• Answer these 2 questions about Evidence 2. Write the letter of your best answer on your sheet.

• Be sure to discuss your answers and your reasons with your partner

• Be sure to put your letter of you answer in the answers diagram on the sheet after you have discussed your answers and your reasons.

Question 3: Which is true of Evidence 2? a. More than half of the children were allergic to cockroach dust. b. Scientists found cockroach dust in kitchens. c. 51% of the children had cockroach dust in their bedrooms. d. 23% of the children had cats in their homes.

Question 4: Which allergy source caused the most allergy attacks in this study? a. Cockroach Dust b. Dust Mites c. Cats d. Pollen

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Evidence 3The Cortez family lives in the apartment across from the Browns. They have 4 children, all boys, and no one in their family has asthma. Mrs. Cortez is sure that the Brown’s boys have asthma because it runs in their family. She knew Grandma Brown had very severe asthma, and when the Brown boys are having trouble breathing, they sound just like Grandma Brown did. She says that the bad asthma genes skipped a generation and were passed down to the Brown boys. The same thing happened to the family of one of Mrs. Cortez’s friends. The grandparents of that family had asthma, and the genes skipped a generation and gave asthma to several of their grandchildren.Conclusion: Mrs. Cortez concluded that the Brown boys have asthma like Grandma Brown did.Back Continue

• Think about how this evidence relates to each of the models that you have seen.

• On your sheet, draw in the arrow that you think best connects this evidence to each of the models. Draw your arrow for Model A in the first column and your arrow for Model B in the second column.

Question 1 and 2: Arrows

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• Answer these 2 questions about Evidence 3. Write the letter of your best answer on your sheet

• Be sure to discuss your answers and your reasons with your partner

Question 3: Based on this evidence, having trouble breathing shows: a. that the boys must have the same condition as their grandma b. that the lungs themselves have become smaller c. that they most likely have asthma caused by cockroach dust d. that the boys have a condition that the doctors don’t know about yet

Question 4: According to this evidence, in the Cortez family: a. all of the children have asthma b. only the boys have asthma c. only the girls have asthma d. no one in their family has asthma

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• Now, go into your packet on page 2 and start working on the remaining questions individually.

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